package com.lcx.security.filter;

import com.lcx.security.security.TokenManager;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.authority.SimpleGrantedAuthority;
import org.springframework.security.core.context.SecurityContextHolder;
import org.springframework.security.web.authentication.www.BasicAuthenticationFilter;

import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

public class TokenAuthFilter extends BasicAuthenticationFilter {

    private TokenManager tokenManager;
    private RedisTemplate redisTemplate;
    public TokenAuthFilter(AuthenticationManager authenticationManager,TokenManager tokenManager,RedisTemplate redisTemplate){
        super(authenticationManager);
        this.redisTemplate = redisTemplate;
        this.tokenManager = tokenManager;
    }

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)throws IOException, ServletException {
        //获取当前认证成功的用户信息
        UsernamePasswordAuthenticationToken authentication = getAuthentication(request);
        //判断 如果有权限信息 放到上下文中
        if(authentication != null){
            SecurityContextHolder.getContext().setAuthentication(authentication);
        }
        chain.doFilter(request,response);
    }


    private UsernamePasswordAuthenticationToken getAuthentication(HttpServletRequest request){
        //从header中获取用户名
        String token = request.getHeader("token");
        if (token!= null){
            //从token中获取用户名
            String username = tokenManager.getUserInfoFromToken(token);

            //从redis获取对应权限列表
            List<String> permissionValueList = (List<String>)redisTemplate.opsForValue().get(username);
            Collection<GrantedAuthority> authorities = new ArrayList<>();
            for (String permissionValue : permissionValueList){
                SimpleGrantedAuthority authority = new SimpleGrantedAuthority(permissionValue);
                authorities.add(authority);
            }
            return new UsernamePasswordAuthenticationToken(username,token,authorities);
        }
        return null;
    }
}
